Well my Father who looks darker skinned but is actually white was arrested by an officer before. But this is where it gets funny, He was arrest for being a belligerent Latino. Funny thing is he is this 6 foot 4 tall guy who is only a little dark skinned. But anyhow all he did was pay for his gas in cash because the credit card wasn't working because we were moving to another state and the bank canceled the card when they saw it going from state to state. So my father was arrested for the night until my mom got him out. We should have sued the department but we didn't.
They may be more on their guard, because these races are more likely tpo commit crime/homicide STATISTICALLY, but 99.98% of the time this doesnt come across in their treatment of offenders. One or two cases of abuse by policemen (nobody's perfect, plus he wasn't giving up and possibly had a gun) is NOT enough evidence to destroy an entire city.
Most cops--most black cops, most Asian cops and most white cops--are good people who are not too harsh with anyone. You can not take a couple of examples of white police officers being too harsh with black suspects and make an assumption like that. There are millions of interactions between black civilians and white cops a year and only a handful evolve excessive use of force.